You have a number of options regarding the syncing method. The syncing method “Shared Folder” can be used with a number of cloud storage systems but does not allow connection to a mobile device such as a phone. The other two syncing methods need a Dropbox Account, at least the free version. The best and most flexible option is called “Dropbox Folder”. However, if you did not purchase direct, but purchased through Apple, due to one of the restrictions Apply impose on Moneydance, you will have to use “Dropbox Connect”. Dropbox Folder requires you to download and install Dropbox Client on all your computers.
When syncing with 2017 you have a primary and a secondary computer. The data set is stored in the default location on the hard drive of your primary computer.
Your second computer does not have the same data set as the primary computer. Its data set is created from data synced via Dropbox folder “.moneydancsync” created automatically by the primary computer.